Conventionally, in filling and capping equipment for filling liquid into a container and capping the container, a cap alignment apparatus (article alignment apparatus) for aligning and feeding caps in various forms is used.
There is an article alignment apparatus as disclosed in Japanese Patent Publication (JP-A) No. 51-47753 (Patent Document 1) in which a cylindrical gutter-shaped member is inclined and rotated and box-shaped articles are put into the gutter-shaped member and are carried from one side to the other side to thereby bring the articles into balanced attitudes and, as a result, align orientations of the articles.
There is an article alignment apparatus as disclosed in Japanese Patent Publication (JP-A) No. 2004-168542 (Patent Document 2) in which, in arranging two columns parallel while inclining them and rotating the columns in reverse directions to each other in such directions as to cause articles to float up due to friction to thereby feed and carry long-columnar articles with heads such as screws and rivets on the two columns, spiral grooves for supporting the articles are formed on surfaces of the two columns to align the long-columnar articles with heads in hanged manners and while leaving spaces between them.
In the article alignment apparatus in Patent Document 1, the center of gravity of a box-shaped article moves as the gutter-shaped member rotates and the center of gravity of the box-shaped article is positioned outside a rotation center of the box-shaped article on the gutter-shaped member to thereby bring down the box-shaped article on a cylindrical face of the gutter-shaped member to bring the box-shaped article into a balanced attitude (attitude with an open face of the box-shaped article up) to align orientations of the box-shaped articles.
However, in the article alignment apparatus in Patent Document 1, the box-shaped article slips against the cylindrical face of the rotating gutter-shaped member and it is difficult to reliably move the center of gravity of the box-shaped article in the above-described manner as the gutter-shaped member rotates and it is difficult to stably and reliably align orientations of the box-shaped articles.
In the article alignment apparatus in Patent Document 2, the long-columnar articles with heads move as the columns rotate and a head portion of the long-columnar article with the head is hanged in the spiral grooves in the surfaces of the columns to thereby carry out alignment of the articles while leaving spaces between them.
However, if the article alignment apparatus in Patent Document 2 tries to align cylindrical articles with top faces such as caps which are not the long-columnar articles with heads, it is difficult to align the articles in a certain orientation, though it is possible to space the articles from each other. The article that has once entered the spiral groove is carried to an outlet while kept in the orientation.